Electronic apparatus



May 12, 1942- H. c. STEINER r-:TAL

ELECTRONIC `APPARATUS Filed Nov. 16, 1940 2 .Sheets-Sheet l MMP-i2, 1942# l' H. c. STEINER ETAL 2,282,901

ELECTRONIC :APPARATUS Filed Novf. 16, 1940 2 sheretseSheel'l 2 i WA@ Inventors: Herr-5 C. Steiner; Eugene Fi Peterson,

Their' Attorney.

Patented May 12, 1942 ELECTRONIC APPARATUS Hairy o. Steiner, sentia, and YEugene F. Petersen,

Schenectady, N. Y., a'ssignors `to General Elec'- tric Company, a corporation of New York Y i Appiieetien November 16, 1940, seriell Ne. 365,936 7 Claims.` (Cl. 25o-.5:15)` The present inventionrelates to arr improved cooling system for electronic power conversion apparatus. n

For heavy duty operation of electronic devices such as arc-discharge rectiers and the like itik is desirable that artificial cooling be provided in order to maintain the operating parts lwithin a i safe range of temperatures. Liquid cooling has frequently been resorted to in' this connection,

butthe difficulty of assuring a continuous supply of `liquid cooling medium somewhat limits'the applicability of this system. Forced air cooling avoids this limitation, but involves the further diiculty of requiring aconsiderable expenditure of power to maintain stdiicient air-now to dissipate large amounts ofheat. y It is an object of the present invention to provide an improved forced-aircooling arrangement for electronic apparatus which arrangement will lessen the amount of power required by the airsupplying agency.y 1n general, the means employed for the attainment ,of this object comprises the combination of a fan of the centrifugal type` and anV apparatusassemblywhich permits a large number of discharge devices to be positioned adjacent to the periphery of the fan and within the region of turbulence Aof the air discharged by it. This disposition of parts not only leads to a Yhighly compactmstructural arrangement butv also makes more eicient Yuse of the fan output than appears possible with cooling arrangements heretofore employed.

A feature of the invention which isapplicable in any system employing Vthe combination of a number of discharge devices with voltage transi formers for energizing them consists in the location of the transformers in a place in which they are exposed to the cooling effect of the stream of air being drawn into the fan casing. This may be done, for example, by establishing the axis of rotation of the fan in avert-ical plane and positioning the transformer below and in proximity to the fanl inlet (e. g. in the base structure which supports the fan).

r'he principles of the invention are illustrated in the accompanying drawings, in which:V n

Fig. 1 is an elevational viewwof one embodiment of the invention, partici the outer housing being broken away to show the internal arrangement of the parts; e

Fig. 2 is a plan view of the embodiment illustratedinFig.l;and*` A v Fig. 3 isv a power conversion circuit whichmay be used with apparatus` Vshown in Figs. 1 and Referring particularly to Figsl and v2 there are shown a'plur'ality of vmtal enclosedl discharge devices (numbered 10` to 15V inclusive) which are located in a 'circular` grouping. Only vthe' eX- terior aspect ofthe devices appears in the drawings but it is assumed that each device is suitable for power conversion purposes. tion, each device may comprise, for example, a

`power rectifier ofthe type Which includes an anode, a mercury pool cathode and a control member for regulating the initiation of a discharge'betweenthe anode and cathode. For the latter purpose one may employ, for example, anY

immersion starting electrode.

In the apparatus illustrated the cathode connection of eachy discharge device comprises a heavy metal stud' (parts I0', I3 and (4') depending from the' bottom of the device envelope, and the corresponding ano'de connection comprises a heavy exibleglead (IDH to l5") insulatin'gly sealed through the top wall of the device. Connections for the-.control elements of certain of the devices are indicated at l1, I8 and 18. All the devices are provided with extended heat-exchange surfacesin the form of externally pro- Yje'ctin-g circular iin's 20 which facilitate'the dissipation of heat. In order to promote selective cooling of the-loweriportion of each device and thus to' permit itsv anode to maintain a higher temperature than the cathode', the upper i'lns are ,more widely spaced than those at the bottom of -the`envelope- A i The space around which the various discharge devices are grouped is occupied by `a centrifugal fan identified as a whole by the numeral 24. This comprises a plurality of appropriately curved vanes 25 arranged in a cage-like formation and is adapted to receive air ataregion adjacent' the aXis ofthe fan and to discharge such air at its periphery. in 4electric-motor 21 having a vertically depending shaft-28 is secured to the fan 'Z4-and, when energized, drivesl the fan at an appropriate operating speed. v

The fan 24 is enclosed by the provision of wall structure which, in combination with the discharge devices. lill-I5 defines a substantially complete chamber.` The wall structure may consist, for example,y of a plurality of sheet metal parts 30' to 3'5 which are so bent as to define radial ducts containing the various discharge devices. Top and bottom Walls 4d' and 4| serve to complete the fan enclosure.L The upper wall lli)v of the fan chamber provides a support for the motor 21, which Yis secured to the ,wall through a In this connecmotor shaft 28 is prevented by means of a suitable packing arrangement indicated at 4T. The bottom wall 4| of the fan chamber has a central opening which permits a continuous flow of air into the fan.

It is apparent that as a result of the arrangement described, air can escape from the fan chamber only by passage in proximity to the discharge devices I to I5. The location of the devices at points relatively closeA to the periphery of the fan further assures that each device shall be within the region of turbulence of air discharged by the fan. Tests show that extremely effective heat exchange is obtained under these circumstances and that for a given ow Aof air, a much greater degree of cooling can be realized than would be possible, for example, by arranging each device at the end of a long air duct or the like. In addition, the symmetrical arrangement of the various devices with respect to the fan, as well as the nature of the fan itself, permits an extremely compact construction of the apparatus as a whole. This facilitates the use `of the apparatus in factories and in other locations where spac'e is'at a premium and also-increases the practicability of moving the apparatus from place to place in cases where mobility is desired.

In the normal use of discharge apparatus of the character described in the foregoing, say, for purposes of rectification or inversion, a considerable amount of auxiliary equipment is necessary. With a structural arrangement such as that shown, this auxiliary equipment may be readily included in the apparatus assembly without increasing the space occupied thereby. Fori example, the transformers needed for supplying power to the various discharge devicesv may be located in the base structure by which the apparatus assembly'is supported. The essential Afeatures of a typical arrangement of this kind are shown in Fig. 1 in which the posts 50 and 5l are assumed to constitute elements of the mounting structure of the electronic' apparatus.

VWithin the space between the posts 50 and 5I p A there is provided a housing 53 which servesjoint? y1y as a duct for supplying air to the fan inlet Vand as a housing for a plurality of transformers yserving for the energization of the discharge devices. One such transformer is illustrated at 55 and isshown as including a plurality of externally projecting vanes 56 which facilitate the vtransfer of heat between the transformer and thev air flowing through the housing 53. "By this means a single air-impelling agency (i. e. the fan 24) is caused to serve for cooling both the discharge devices and the power supply apparatus.

'I'he various transformers enclosed by the housing 53 may be connected with the discharge devices by means of insulated conductors Yextending upwardly through the' free spaces provided within the wall parts 30 to 35. This is exemplified by the conductor 58 which connects with the anode lead I0 of the discharge device |70. It is customaryin apparatus of the type 'under consideration to provide a fuse link or similar safety device in circuit between the transformer and its associated discharge device. This is conveniently accomplished in the present instance by the provision at the top of the apparatus assembly of a hexagonal panel board 60 Vupon which a number of fuses (exemplified at proximity to the be readily mounted within the compartments formed by the convolutions of wall parts 30 to '35. This possibility is illustrated by tubes 68, 69 and 10 which are shown within certain of the compartments together with schematically indicated auxiliary elements 11,112 and 13. For the sake of simplicity the connections between the tubes 68-10 and the main discharge devices are not shown.

The electrical aspects of a typical power conversion apparatus of the character illustrated in Figs. 1 ,and 2 are shown in Fig. 3. In this figure there are illustrated a plurality of electric discharge devices I0 to l5, these being assumed to correspond in essential particulars to the similarly numbered devices of Fig. 1. The devices are used to transmit energy from a polyphase alternating current supply circuit 15 to a direct current load circuit 16. To this end, the supply circuit 15 is connected with the primaries 18, 19, .of a plurality of transformers connected in delta. Each of the transformers is assumed to beprovided with a 'pair of secondary windings (18"and 18", 19 and 19" and 80 and 80"), these secondaries being connected in a double Y arrangement -as shown. VThe neutral points of the two Ys are connected through an interphase reactor 83 to produce a `six-phase system. The midpoint 84 of thereactor 83 is connected to one side of the direct current circuit 16 while the other side'of the 'direct current circuitisconnected in common lto the cathodes of devices I Il to l5. The' terminals of the various secondary windings vare connected with the anodes of the devices through V,appropriate fuse links indicated at 86 to 9| in- '.clusive.

I'he operation of the-various discharge devices is controlled by the starting electrodes associated with' the devices, Aand it is assumed in Vthisl connection that Ieach of the illustrated starting electrodes is'connected to an appropriate control circuit. viously form no part of the present invention, they'are not specifically illustrated.) By means of the control circuits, the various discharge'devices are caused to conduct intermittently and sequentially in such fashion as" to supply a rectied potential to the terminals 16. v

The foregoing description of Fig. 3 illustrates the vdiverse character of electrical apparatus which maybe advantageously incorporated in a structural arrangement such as that illustrated in Figs. 1 and 2; It will be observed in this connection that all the elements of the circuit of Fig. 3 are represented in their structural counterparts in the apparatus shown in Fig. 1. While the invention has been described by reference toa particular embodiment thereof, it will be understood that numerous modifications may be made by those skilled inthe art without departing from the invention. We therefore aim in the appended claims to cover all such equivalent lvariations as come within the true spirit and scope ofthe foregoing disclosure.

What we'claim as new anddesire tosecure by Letters Patent of the United States is: A

l. An improved arrangement for electronic power conversion apparatus comprising a plurality of electronic discharge devices grouped aroundia given center, a vcentrifugal fan having .its axis of rotation at least approximately coin- (Since the control circuitsob cident with said center, structure cooperating with said discharge devices to define a generally cylindrical chamber 'enclosing the fan, the chamber being formed to assure that air discharged by the fan shall escape from the chamber mainly by passage in proximity to the discharge devices, and an inlet to the chamber for maintaining a supply of air to the fan.

2. An improved arrangement for electronic power conversion apparatus comprising a fan of the centrifugal type, wall structure defining a generally cylindrical chamber enclosing the fan, said chamber having a plurality of openings disposed about the periphery of the fan and permitting the escape from the chamber of air discharged by the fan, a plurality of electronic discharge devices respectively disposed in and incompletely lling the said openings, the said discharge devices being in suiicient proximity to the periphery of the said fan to be within the region of turbulence of air discharged by the fan, and means for supplying air to the fan to maintain continuous cooling of the discharge devices.

3. An improved arrangement for electronic power conversion apparatus comprising a fan of the centrifugal type, means defining a cylindrical chamber enclosing the fan and providing a plurality of radial ducts for permitting the escape of air discharged by the fan, a plurality of electric discharge devices respectively disposed in and incompletely filling the said ducts, and an inlet to the chamber for supplying air to the fan so as to maintain continuous cooling of the discharge devices.

4. An improved arrangement for electronic power conversion apparatus comprising a fan of the centrifugal type, means defining a cylindrical chamber enclosing the fan, said chamber having a plurality of peripheral openings therein for permitting the escape from the chamber oi air discharged by the fan, a plurality of metal enclosed electronic discharge devices respectively positioned in the various openings and incompletely lling the same, extended heat-exchange surfaces respectively connected with the containers of the several discharge devices, and means for supplying air to the fan to eiect continuous cooling of the said heat-exchange surfaces.

-5. An improved arrangement for electronic power conversion apparatus comprising a fan of the centrifugal type having its axis of rotation in a verti-cal plane, wall structure dei'lning a chamber enclosing the fan,'said chamber havin-g a plurality of openings disposed about the periphery of the ian and permitting the escape from the chamber of air discharged by the fan, a plurality of electronic discharge devices respectively disposed in and incompletely filling the said openings, a motor supported on the upper wall of the said chamber for driving thesaid fan, and means for supplying air to the fan through the lower wall of the chamber to effect continuous cooling of the discharge devices.

6. An improved arrangement for electronic power conversion apparatus comprising a fan of the centrifugal type, means defining a cylindrical chamber enclosing the fan, said chamber having a plurality of peripheral openings therein for permitting the escape of air discharged by the fan, a plurality of electronic discharge devices respectively positioned in the various openings and incompletely closing the same, whereby the devices are cooled by air discharged through the open- I ings, a voltage transformer connecting with at least certain of the discharge devices for energizing the source, said transformer b'eing located adjacent to the fan-enclosing chamber, and an air inlet for the chamber positioned to assure that air supplied to the chamber shall initially pass in heat-exchanging relation with the transformer.

7. An improved arrangement for electronic power conversion apparatus comprising a centrifugal fan having its axis of rotation in a vertical plane, means dening a cylindrical cham` ber enclosing the fan, said chamber having a plurality of peripheral openings for permitting the escape of air discharged by the fan, a plurality of electronic discharge devices respectively positioned in the said openings and incompletely closing the same, whereby the devices are cooled by air passing through the openings, a

base structure supporting the said fan and ydis- 

